The invention relates to forming articles, and in particular to forming toothbrush bodies.
Toothbrushes generally include a toothbrush body that includes a handle portion and a head portion, and tufts of bristles located at or near the head portion.
Toothbrush bodies are generally made by injection molding machines. These toothbrush bodies often consist of plastic and include multiple components. The different components may differ in nature, color, texture, density, and hardness. For example, toothbrush bodies may include a relatively hard plastic base component and a colored rubberized gripping component.
After the toothbrush bodies are manufactured they are automatically removed from the molding machine and deposited onto a cooling conveyor. The cooling conveyor transports the toothbrush bodies to a bin. The bodies are then manually transported to a bristle tufting machine where they receive tufts of bristles and are formed into toothbrushes.
The tufting operation generally involves manually grabbing handfuls of differently colored toothbrush bodies so as to provide a mixture of differently colored toothbrush bodies to a hopper. A conveyor removes the toothbrush bodies randomly from the hopper and orients the bodies so that the head portion of the body is available to receive the tufts of bristles from the bristle tufting machine. The bristle tufting machine automatically staples tufts of bristles into the head of each toothbrush body to form a toothbrush. The finished toothbrushes are automatically deposited into a tray which is manually transported to a packaging machine.
In one aspect, the invention features an apparatus that includes a mold that includes a first cavity defining a toothbrush body, a first injection unit in fluid communication with the first cavity, and a second injection unit also in fluid communication with the first cavity.
In one embodiment, the apparatus further Includes a second cavity defining a second toothbrush body. The second cavity is in fluid communication with the first injection unit. In another embodiment, the apparatus further includes a third cavity defining a third toothbrush body. The third cavity is in fluid communication with the second injection unit. Preferably the first and second injection units are in alternate fluid communication with the first cavity.
In other embodiments, the mold further includes a fourth cavity defining a fourth toothbrush body, and the apparatus further includes a third injection unit. The third injection unit is in fluid communication with the third cavity and the fourth cavity. Preferably the second and third injection units are in alternate fluid communication with the third cavity.
The injection units are capable of substantially simultaneously injecting a first molding compound having a first property into the second cavity, injecting a second molding compound having a second property into the third cavity, and injecting either the first or the second molding compound into the first cavity to form toothbrush bodies having different properties.
In another embodiment, the apparatus further includes a gating device in fluid communication with the first and second injection units. The gating device is capable of directing the flow of molding compound to the first cavity such that either the first injection unit is in fluid communication with the first cavity or the second injection unit is in fluid communication with the first cavity.
In another embodiment, the apparatus further includes a) a second mold that includes a cavity defining a toothbrush body, b) a third injection unit in fluid communication with the second mold cavity, and c) an automated mechanical transfer for transferring a toothbrush body from the cavity of the second mold to the cavity of the first mold.
In another aspect, the invention features an apparatus that includes a mold that includes a first cavity defining a toothbrush body, and a second cavity defining a toothbrush body. The first cavity and the second cavity define substantially identical toothbrush bodies. The apparatus also includes a first injection unit in fluid communication with the first cavity, and a second injection unit in fluid communication with the second cavity. In one embodiment, the injection units are capable of injecting a first molding compound having a first property into the first cavity to form a toothbrush body having a first property, and injecting a second molding compound having a second property into the second cavity to form a toothbrush body having a second property. Preferably the injection units are capable of substantially simultaneously injecting the molding compounds into the cavities.
In another aspect, the invention features an apparatus for substantially simultaneously molding a plurality of substantially similar toothbrush bodies such that at least one of the toothbrush bodies has a property that is different from another of the toothbrush bodies.
In other aspects, the invention features a process for substantially simultaneously forming toothbrush bodies having different properties in one mold. The process includes: a) selecting a first injection unit from a group of at least two injection units in fluid communication with a first mold cavity, b) injecting a first molding compound from the first injection unit into the first cavity to form a toothbrush body having a first property, and c) injecting a second molding compound, different from the first molding compound, into a second cavity of the mold to form a toothbrush body having a second property. In one embodiment, the step of injecting a first molding compound, and the step of injecting a second molding compound occur substantially simultaneously. Preferably the first toothbrush body includes a first color and the second toothbrush body includes a second color. The second color is different from the first color.
In another embodiment, the process for forming a toothbrush body includes a) injecting a first molding compound into a first mold cavity to form a first toothbrush body, b) transferring the first toothbrush body to a second mold cavity, the second mold cavity defining a second toothbrush body, c) selecting a first injection unit from a group of at least two injection units in fluid communication with the second mold cavity, and d) injecting a second molding compound from the first injection unit into the second mold cavity to form a second toothbrush body.
In one embodiment, the process for forming toothbrush bodies having different properties includes a) injecting a first molding compound into a plurality of first mold cavities to form a plurality of first toothbrush bodies, b) transferring the first toothbrush bodies to a plurality of second mold cavities, c) selecting a first injection unit from a group of at least two injection units in fluid communication with one of the second mold cavities, d) injecting a second molding compound from the first injection unit into the second mold cavity to form a second toothbrush body having a first property; and e) injecting a third molding compound into another of the second mold cavities to form a second toothbrush body having a second property.
In another aspect, the invention features a process for substantially simultaneously forming toothbrush bodies having different properties in one mold, where the mold includes a first cavity defining a toothbrush body and a second cavity defining a toothbrush body and the first cavity and the second cavity define substantially similar toothbrush bodies. The process includes (a) injecting a first molding compound into the first cavity of the mold to form a toothbrush body having a first property, and (b) injecting a second molding compound, different from the first molding compound, into the second cavity of the mold to form a toothbrush body having a second property. Preferably the first property is a first color and the second property is a second color.
In other aspects, the invention features an apparatus that includes a) a mold that includes a first cavity defining an article; b) a first injection unit in fluid communication with the first cavity; and c) a second injection unit also in fluid communication with the first cavity. In other embodiments, the apparatus includes (a) a mold that includes a first cavity defining an article, and a second cavity defining an article, the first cavity and the second cavity define substantially similar articles; (b) a first injection unit in fluid communication with the first cavity; and (c) a second injection unit in fluid communication with the second cavity.
In another aspect the invention features a process for substantially simultaneously forming articles having different properties in one mold. The process includes a) selecting a first injection unit from a group of at least two injection units in fluid communication with a first mold cavity; b) injecting a first molding compound from the first injection unit into the first cavity to form an article having a first property; and (c) injecting a second molding compound, different from the first molding compound, into a second cavity of the mold to form an article having a second property.
In another embodiment, the process for forming articles having different properties includes a) injecting a first molding compound into a plurality of first mold cavities to form a plurality of first articles; b) transferring said first articles to a plurality of second mold cavities; c) selecting a first injection unit from a group of at least two injection units in fluid communication with one of said second mold cavities; d) injecting a second molding compound from the first injection unit into one of said second mold cavities to form a second article having a second property; and e) injecting a third molding compound into another of said second mold cavities to form a second article having a third property.
As used herein, the term xe2x80x9ctoothbrush bodyxe2x80x9d is intended to refer to any portion of the toothbrush body, e.g., the entire toothbrush body including the head portion and the handle portion; the head portion; the handle portion; portions of the head portion; and portions of the handle portion.
The invention permits the manufacture of articles (e.g., toothbrush bodies) having a predetermined variety of properties (e.g., different colors) from a single mold in a single molding cycle. This in turn allows control over the subsequent manufacture and packaging of toothbrushes such that single packages of multiple toothbrushes can be manufactured where each package contains a predetermined multiple of toothbrushes having different properties (e.g., a predetermined number of red, yellow or blue handled toothbrushes in a single package). The invention also permits the selection of a predetermined variety of articles to achieve an array of articles having a variety of properties. The present invention thus avoids the need for manual intervention or assistance in the mixing of toothbrushes to achieve a desired mixture of toothbrushes having different properties in a single package. The apparatus also provides control over the color mixture in each package of toothbrushes shipped to a customer.
The arrangement of the injection units in the molding unit also advantageously permits variation in injection timing which allows molding compounds having differing cure rates to be injected into mold cavities at different times so that cure is completed substantially simultaneously for each molding compound. This allows a single mold cycle to accommodate a variety of molding compounds.
The apparatus of the present invention is also capable of producing an ordered array of toothbrush bodies and maintaining the relative order of the toothbrush bodies throughout the manufacturing process. Maintenance of the ordered array also simultaneously maintains the orientation of the toothbrush bodies, which facilitates tufting and packaging processes.
Other features and advantages of the invention will become apparent from the following description of the preferred embodiments thereof, and from the claims.